THE United States Coast Guard (USCG) and Philippine Coast Guard (PCG) were reported to have carried out what appears to be the first publicly tracked joint maritime presence operation near Bajo de Masinloc (Scarborough Shoal), amid continuing tensions in the West Philippine Sea.
The operation, based on data cited in maritime monitoring reports from US-based transparency group SeaLight and referenced by Starboard Intel, showed the USCG cutter Midgett departing Manila Bay on May 28 alongside the PCG cutter BRP Melchora Aquino.
The vessels were later tracked, positioning themselves on the western approaches to Bajo de Masinloc beginning May 29, maintaining an estimated distance of 35 to 40 nautical miles from the shoal.
The reported joint presence comes amid overlapping maritime activity involving other Philippine government vessels.
The PCG patrol vessel BRP Cabra and the Bureau of Fisheries and Aquatic Resources (BFAR) vessel BRP Datu Pagbuaya were also observed operating in the broader area.
The BFAR vessel was later seen returning toward Manila Bay while being closely shadowed by China Coast Guard vessel CCG 21563, based on AIS data cited in the same reports.
Other Philippine assets were believed to be operating in the vicinity but were not broadcasting Automatic Identification System (AIS) signals, leaving their positions unconfirmed in publicly available tracking data.
On the opposing side, AIS tracking reportedly showed a layered Chinese maritime deployment around Scarborough Shoal.
At least nine China Coast Guard vessels were identified forming an outer perimeter approximately 20 to 40 nautical miles from the shoal, while at least seven larger maritime militia vessels were observed forming an inner cordon closer in, between roughly 5 and 17 nautical miles.
The reports also noted the possible presence of additional People’s Liberation Army Navy (PLAN) vessels in the area that were not visible on AIS.
These naval assets have historically operated in the background of similar standoffs but typically do not broadcast their positions.
Maritime observers cited in the report described the reported US Coast Guard participation alongside Philippine Coast Guard vessels as a significant development in alliance activity in the West Philippine Sea, given the proximity of operations to Scarborough Shoal, a long-standing flashpoint between Manila and Beijing.
Bajo de Masinloc remains under de facto control of China through coast guard and maritime militia deployments, while the Philippines continues to assert its claims over the feature and maintain regular patrols and civilian support operations in surrounding waters, particularly through the BFAR.
Maritime monitoring groups emphasized that vessel positioning and AIS patterns suggest a coordinated multi-asset presence involving US, Philippine, and Chinese maritime forces operating in close proximity.
However, the reports noted that no official statements confirming the tactical objectives of the operation have been released.
The situation remains fluid, with vessel movements subject to change and not fully verifiable beyond publicly available tracking data referenced in the initial maritime monitoring reports.
Meanwhile, Defense Secretary Gilberto Teodoro Jr. said the Philippine government is monitoring what he described as “raw information” regarding possible new structures in Bajo de Masinloc, stressing that developments in the area are being closely watched amid its strategic sensitivity.
“There is raw information. Actually, I am saying that Bajo de Masinloc is a dynamic area, so although developments are still small, these are already being monitored,” Teodoro said on Saturday.
Teodoro said the information being received has not yet been fully validated but is being treated seriously given the importance of the West Philippine Sea.
His remarks come amid continued Philippine surveillance of activity around Scarborough Shoal, where maritime tensions have persisted for years.
Earlier assessments by Philippine maritime authorities have consistently reported the presence of Chinese coast guard and maritime militia vessels in surrounding waters, while noting that no confirmed new permanent structures have been established on the shoal in recent monitoring updates.
Defense and security officials have previously clarified that periodic reports of suspected installations or unusual features in the area remain subject to verification and continuous surveillance.
Teodoro did not provide further details on the reported “raw information,” but said even small-scale developments in the area are being closely tracked as part of ongoing maritime domain awareness efforts.
